updated 03:31 pm EDT, Tue August 20, 2013

Ads to eventually become device-specific

A number of major advertisers have lined up to advertise on Apple's upcoming iTunes Radio service. According to Ad Age, the list so far includes "McDonald's, Nissan, Pepsi, Procter & Gamble and possibly one or two more brands," all of whom have reportedly signed 12-month contracts. Targeting will initially be device-agnostic, but in 2014 advertisers will get the option to direct spots at specific devices, with costs varying proportionately. An ad will be cheap on the iPhone, for instance, but more expensive on an iPad, and even more costly on an Apple TV.

Listeners should expect an audio ad every 15 minutes, and a video ad every hour, Ad Age's sources say. People will be forced to see the video ads at times they're likely looking their screen, such as after hitting the Play or Skip buttons.

Apple is also allowing advertisers to curate their own stations. Company names will be barred from appearing in station titles, but businesses will be allowed to insert pre-play messages branding the content.

iTunes Radio is slated to go live around the same time as iOS 7, which is anticipated next month. People will be able to forego ads only by paying for an iTunes Match subscription, which costs $25 per year.